Response surface methodology (RSM) was adopted to study the key parameters such as acid leaching time, calcined temperature, calcined time in order to increase silicon dioxide extracting rate from rice husk. A second order quadratic equation was established and the applicability of model and interaction involved factors on predicting the SiO2 extracting rate was verified. The results indicated that the effect on the SiO2 extracting rate was as follows: calcined time, acid leaching time, calcined temperature. The optimal levels for achieving the highest SiO2 extracting rate were obtained ,including calcined time of 1.495 hour, acid leaching time of 36 hour, calcined temperature of 620°C. The SiO2 extracting rate reached 73.4% under optimized conditions. Extracting rate were conducted under the optimum condition and the results showed the models fitted well.The products XRD diffraction analysis proved that it was amorphous SiO2 .